Low cost planar image intensifier tube structure

Abstract

An image intensifier tube is provided. The image intensifier tube has a microchannel plate (MCP), a photocathode and phosphor screen deposited on a fiber optic substrate. A first spacer is positioned between the microchannel plate and the fiber optic substrate. A second spacer is positioned between the fiber optic substrate and the photocathode. The first and second spacers cooperate to provide a spatial relationship among the MCP, phosphor screen and photocathode for effective operation of the image intensifier tube.

1. An image intensifier tube comprising:
 a microchannel plate; 
 a photocathode assembly including a photocathode disposed on a substrate; 
 a fiber optic substrate defining a planar surface; 
 a phosphor screen deposited on the planar surface of the fiber optic substrate; 
 a first spacer positioned in direct contact with both said microchannel plate and said planar surface of said fiber optic substrate; and 
 a second spacer positioned in direct contact with both said photocathode assembly and said planar surface of said fiber optic substrate, 
 wherein said first and second spacers cooperate to provide a spatial relationship among the MCP, phosphor screen and photocathode assembly for effective operation of the image intensifier tube. 
 
     
     
       2. The image intensifier tube of  claim 1  further comprising a getter positioned between the fiber optic substrate and the photocathode assembly. 
     
     
       3. The image intensifier tube of  claim 2 , wherein said getter is an evaporable getter configured to maintain a vacuum within an interior cavity of the image intensifier tube. 
     
     
       4. The image intensifier tube of  claim 2 , wherein said getter is a non-evaporable getter configured to maintain a vacuum within an interior cavity of the image intensifier tube. 
     
     
       5. The image intensifier tube of  claim 2 , wherein said getter comprises a substantially flat cylindrical ring. 
     
     
       6. The image intensifier tube of  claim 2  further comprising a getter shield positioned adjacent to said getter and between the fiber optic substrate and the photocathode assembly. 
     
     
       7. The image intensifier tube of  claim 1  wherein said first spacer is fixed to the microchannel plate and the fiber optic substrate with a conductive epoxy. 
     
     
       8. The image intensifier tube of  claim 1  wherein said first spacer is fixed to the microchannel plate and the fiber optic substrate by a soldering process. 
     
     
       9. The image intensifier tube of  claim 1  further comprising a plurality of conductive vias provided through said fiber optic substrate and extending to said planar surface of said fiber optic substrate;
 at least one conductive via extending to said planar surface of said fiber optic substrate for providing electrical potential to said phosphor screen. 
 
     
     
       10. The image intensifier tube of  claim 9 , said first spacer defining two conductive regions, wherein each conductive region of said first spacer is positioned in contact with a conductive via extending to said planar surface of said fiber optic substrate. 
     
     
       11. The image intensifier tube of  claim 10 , said MCP having a first conductive region positioned in contact with one of the conductive regions of said first spacer and a second conductive region positioned in contact with the other conductive region of said first spacer for providing electrical potential to said MCP. 
     
     
       12. The image intensifier tube of  claim 11 , wherein each conductive region of said first spacer extends from a bottom surface of said first spacer to a top surface of said first spacer. 
     
     
       13. The image intensifier tube of  claim 12 , wherein said first spacer is a substantially flat cylindrical ring comprising said top surface, said bottom surface and two annular side surfaces extending between said top surface and said bottom surface of said first spacer,
 wherein each conductive region includes a conductive portion defined on said bottom surface, at least one side surface and said top surface of said first spacer. 
 
     
     
       14. The image intensifier tube of  claim 12 , wherein each conductive region disposed on said top surface of said first spacer is positioned in contact with either said first conductive region of said MCP or said second conductive region of said MCP for providing electrical potential to said MCP. 
     
     
       15. The image intensifier tube of  claim 14 , wherein one of said conductive regions of said MCP extends from a bottom surface of said MCP to a top surface of said MCP for providing electrical potential to said top surface of said MCP, and the other conductive region of said MCP is disposed on said bottom surface of said MCP for providing electrical potential to said bottom surface of said MCP,
 wherein said bottom surface of said MCP is positioned in contact with said top surface of said first spacer. 
 
     
     
       16. An image intensifier tube comprising:
 a fiber optic substrate defining a planar surface; 
 a phosphor screen deposited on said planar surface of said fiber optic substrate, 
 a plurality of conductive vias provided through said fiber optic substrate and extending to said planar surface of said fiber optic substrate; 
 at least one conductive via extending to said planar surface of said fiber optic substrate for providing electrical potential to said phosphor screen; 
 a spacer positioned on said planar surface of said fiber optic substrate, said spacer defining two conductive regions, wherein each conductive region of said spacer is positioned in contact with a conductive via extending to said planar surface of said fiber optic substrate; and 
 a microchannel plate (MCP) positioned on said spacer, said MCP having a first conductive region positioned in contact with one of the conductive regions of said spacer and a second conductive region positioned in contact with the other conductive region of said spacer for providing electrical potential to said MCP. 
 
     
     
       17. The image intensifier tube of  claim 16  further comprising a getter contact disposed on the planar surface of said fiber optic substrate and conductively coupled to a getter. 
     
     
       18. The image intensifier tube of  claim 17  further comprising at least one conductive via provided through said fiber optic substrate and conductively coupled to said getter contact. 
     
     
       19. The image intensifier tube of  claim 17  wherein said getter contact is a layer of thin film. 
     
     
       20. The image intensifier tube of  claim 16  wherein at least one conductive via comprises a frit seal assembly extending through an aperture disposed within said fiber optic substrate. 
     
     
       21. The image intensifier tube of  claim 16  wherein said fiber optic substrate is at least partially composed of glass. 
     
     
       22. The image intensifier tube of  claim 16 , wherein each conductive region of said spacer extends from a bottom surface of said spacer to a top surface of said spacer. 
     
     
       23. The image intensifier tube of  claim 22 , wherein said spacer is a substantially flat cylindrical ring comprising said top surface, said bottom surface and two annular side surfaces extending between said top surface and said bottom surface,
 wherein each conductive region includes a conductive portion defined on said bottom surface, at least one side surface and said top surface of said spacer. 
 
     
     
       24. The image intensifier tube of  claim 22 , wherein each conductive region disposed on said top surface of said spacer is positioned in contact with either said first conductive region of said MCP or said second conductive region of said MCP for providing electrical potential to said MCP. 
     
     
       25. The image intensifier tube of  claim 24 , wherein one of said conductive regions of said MCP extends from a bottom surface of said MCP to a top surface of said MCP for providing electrical potential to said top surface of said MCP, and the other conductive region of said MCP is disposed on said bottom surface of said MCP for providing electrical potential to said bottom surface of said MCP,
 wherein said bottom surface of said MCP is positioned in contact with said top surface of said spacer. 
 
     
     
       26. An image intensifier tube comprising:
 a ceramic header defining a planar surface; 
 a silicon imager including silicon disposed on said planar surface of said ceramic header; 
 a plurality of conductive vias provided through said ceramic header and extending to said planar surface, at least one of said conductive vias being positioned for providing electrical potential to said silicon imager; 
 a spacer positioned on said planar surface of said ceramic header, said spacer defining two conductive regions, wherein each conductive region of said spacer is positioned in contact with a conductive via extending to said planar surface of said ceramic header; and 
 a microchannel plate (MCP) positioned on said spacer, said MCP having a first conductive region positioned in contact with one of the conductive regions of said spacer and a second conductive region positioned in contact with the other conductive region of said spacer for providing electrical potential to said MCP. 
 
     
     
       27. The image intensifier tube of  claim 26  wherein the silicon imager is a complementary metal oxide semiconductor (CMOS). 
     
     
       28. The image intensifier tube of  claim 27 , wherein at least one conductive via comprises a frit seal assembly extending through an aperture disposed within said ceramic header and conductively coupled to said complementary metal oxide semiconductor. 
     
     
       29. The image intensifier tube of  claim 26  wherein the silicon imager is a charged coupled device (CCD). 
     
     
       30. The image intensifier tube of  claim 29 , wherein at least one conductive via comprises a frit seal assembly extending through an aperture disposed within said ceramic header and conductively coupled to said charged coupled device. 
     
     
       31. The image intensifier tube of  claim 26  further comprising a photocathode assembly including a photocathode disposed on a substrate, and another spacer positioned between said photocathode assembly and said planar surface of said ceramic header. 
     
     
       32. The image intensifier tube of  claim 31  wherein said spacers cooperate to provide a spatial relationship among the MCP, photocathode assembly and silicon imager for effective operation of the image intensifier tube. 
     
     
       33. The image intensifier tube of  claim 32 , wherein said spacers are incorporated into said ceramic header. 
     
     
       34. The image intensifier tube of  claim 26  further comprising a getter positioned adjacent the ceramic header. 
     
     
       35. The image intensifier tube of  claim 34  wherein said getter is an evaporable getter configured to maintain a vacuum within an interior cavity of the image intensifier tube. 
     
     
       36. The image intensifier tube of  claim 34  further comprising a getter shield positioned adjacent to said getter and said ceramic header. 
     
     
       37. The image intensifier tube of  claim 26 , wherein each conductive region of said spacer extends from a bottom surface of said spacer to a top surface of said spacer. 
     
     
       38. The image intensifier tube of  claim 37 , wherein said spacer is a substantially flat cylindrical ring comprising said top surface, said bottom surface and two annular side surfaces extending between said top surface and said bottom surface,
 wherein each conductive region includes a conductive portion defined on said bottom surface, at least one side surface and said top surface of said spacer. 
 
     
     
       39. The image intensifier tube of  claim 37 , wherein each conductive region disposed on said top surface of said spacer is positioned in contact with either said first conductive region of said MCP or said second conductive region of said MCP for providing electrical potential to said MCP. 
     
     
       40. The image intensifier tube of  claim 39 , wherein one of said conductive regions of said MCP extends from a bottom surface of said MCP to a top surface of said MCP for providing an electrical potential to said top surface of said MCP, and the other conductive region of said MCP is disposed on said bottom surface of said MCP for providing an electrical potential to said bottom surface of said MCP,
 wherein said bottom surface of said MCP is positioned in contact with said top surface of said spacer. 
 
     
     
       41. A method of assembling an image intensifier tube comprising the steps of:
 depositing a phosphor screen on a planar surface of a fiber optic substrate; 
 positioning a plurality of conductive vias through the fiber optic substrate to extend to the planar surface of the fiber optic substrate, wherein at least one of the conductive vias is positioned to provide electrical potential to the phosphor screen; 
 positioning a spacer above and in direct contact with the planar surface of the fiber optic substrate; 
 orienting the spacer such that a first conductive region defined on the spacer is aligned with one of said conductive vias and a second conductive region defined on the spacer is aligned with another of said conductive vias; 
 positioning a microchannel plate above and in direct contact with the spacer; and 
 orienting the MCP such that a first conductive region of the MCP is aligned with the first conductive region of the spacer and a second conductive region of the MCP is aligned with the second conductive region of the spacer to provide electrical potential to said MCP. 
 
     
     
       42. The method of  claim 41  further comprising the step of fixing the spacer to the microchannel plate via braze, solder or epoxy. 
     
     
       43. The method of  claim 41  further comprising the step of positioning a second spacer on the planar surface of the substrate. 
     
     
       44. The method of  claim 43  further comprising the step of positioning a photocathode assembly above and in contact with the second spacer. 
     
     
       45. The method of  claim 44  further comprising the step of positioning a centering ring around the photocathode assembly, second spacer and fiber optic assembly to substantially enclose the image intensifier tube. 
     
     
       46. The method of  claim 45  further comprising the steps of positioning an indium decal between the centering ring and photocathode assembly; and
 applying pressure to the indium decal to hermetically seal the image intensifier tube. 
 
     
     
       47. The method of  claim 45  further comprising the steps of positioning an indium decal between the centering ring and fiber optic assembly; and
 applying pressure to the indium decal to hermetically seal the image intensifier tube.